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ObjectiveTo investigate the effects and mechanism of Zuogui Jiangtang Tongmai prescription (ZJTP) on human umbilical vein endothelial cells (HUVECs) damaged by high glucose combined with lipopolysaccharide (LPS). MethodThe survival rate of cells was determined by cell counting kit-8 (CCK-8), and the level of tumor necrosis factor-α (TNF-α) was determined by enzyme-linked immunosorbent assay (ELISA) to determine the optimal injury concentration and action time of LPS, as well as the optimal action concentration of ZJTP drug-containing serum. HUVECs were divided into a blank control group, a model group, a ZJTP drug-containing serum group, and an SCFA mixed liquid group. ELISA was used to detect the level of endothelin-1 (ET-1), nitric oxide (NO), interleukin-1β (IL-1β), interleukin-6 (IL-6), and TNF-α. Western blot was performed to detect the protein expression of G protein-coupled receptor43 (GPR43), β-suppressor protein-2 (β-arrestin-2), nuclear factor-κB suppressor α (IκBα), and nuclear factor κB p65 (NF-κB p65). The nucleation of NF-κB p65 was observed by immunofluorescence staining (IF). The role of GPR43 in the regulation of inflammatory injury was observed by means of small interfering ribonucleic acid (siRNA). The cells after intervention were divided into an empty carrier group, a ZJTP drug-containing serum group, a Si-GPR43 group, and a Si-GPR43 + ZJTP drug-containing serum group. The content of IL-1β, IL-6, and TNF-α was detected by ELISA. The protein expression of pathways was detected by Western blot. IF was used to observe the nucleation of NF-κB p65. ResultThe optimal molding condition was 1 mg·L-1 LPS for 24 h. The optimal drug intervention condition was 5% ZJTP drug-containing serum for 24 h. Compared with the blank control group, the content of ET-1 in the model group was significantly increased, and the content of NO was significantly decreased (P<0.01). The levels of inflammatory factors were significantly increased (P<0.01). The expressions of GPR43 and IκBα were significantly decreased, while the protein expressions of β-arrestin-2 and NF-κB p65 were significantly increased (P<0.01). NF-κB p65 protein was transferred from the extranuclear to the intranuclear (P<0.01). Compared with the model group, the content of ET-1 in the ZJTP drug-containing serum group was decreased, and the content of NO was increased (P<0.05). The levels of inflammatory factors decreased (P<0.05). The protein expressions of GPR43 and IκBα were increased, while the expressions of β-arrestin-2 and NF-κB p65 were decreased (P<0.05). The amount of NF-κB p65 transferred from the intranuclear to the extranuclear decreased (P<0.01). The mechanism study showed that compared with the Si-GPR43 group, the content of IL-1β, IL-6, and TNF-α were significantly decreased after treatment with ZJTP drug-containing serum (P<0.01). The protein expressions of GPR43 and IκBα were significantly increased (P<0.01), while the protein expressions of β-arrestin-2 and NF-κB p65 were significantly decreased (P<0.01). The amount of NF-κB p65 transferred from the extranuclear to the intranuclear decreased (P<0.01). ConclusionZJTP has a protective effect on HUVECs with high glucose and LPS-induced inflammatory injury, which may be related to the regulation of GPR43/β-arrestin-2/IκBα/NF-κB pathway.
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ObjectiveTo investigate the intervention effect of Jiedu Tongluo Tiaogan prescription (JTTP) in protecting pancreatic β cells by targeting the bile acid Takeda G protein-coupled receptor 5 (TGR5)/cyclic adenosine monophosphate (cAMP) signaling pathway against NOD-like receptor protein 3 (NLRP3) inflammasome. MethodThirty-two male SPF-grade db/db mice were randomly divided into the model group, low-dose JTTP group (3.6 g·kg-1), high-dose JTTP group (7.2 g·kg-1), and metformin group (0.2 g·kg-1). Eight db/m mice were assigned to the blank control group. The mice were treated with drugs for 8 weeks, and fasting blood glucose (FBG) was measured every 2 weeks. Oral glucose tolerance tests (OGTT) were conducted after the last administration. Enzyme-linked immunosorbent assay (ELISA) was performed to detect fasting insulin (FINS), and the homeostasis model assessment of β-cell function (HOMA-β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and IL-1β levels were calculated. Hematoxylin-eosin (HE) staining was used to observe pathological changes in mouse pancreatic tissue. Immunofluorescence was performed to detect insulin expression in mouse pancreatic tissue. Western blot and real-time quantitative polymerase chain reaction (Real-time PCR) were used to detect the expression of proteins and mRNAs of key targets in the TGR5/cAMP signaling pathway and NLRP3 inflammasome. ResultCompared with blank group, FBG, OGTT, FINS, IL-6, TNF-α and IL-1β in model group were significantly increased (P<0.01). Compared with model group, after 6 weeks of drug treatment, FBG level in JTTP group and metformin group decreased significantly (P<0.01). The results of OGTT experiment showed that compared with model group, the blood glucose levels of mice in each administration group were decreased at all time points (P<0.05, P<0.01), and the levels of FINS, TNF-α and IL-6 in JTTP dose groups and metformin group were significantly decreased. The level of IL-1β in JTTP high-dose group and metformin group was significantly decreased (P<0.01). Pancreatic pathology showed that the islets in the model group were irregular in shape, uneven in distribution, and showed signs of atrophy. The prognosis of JTTP was that the cell count increased and the boundary was clearer. Immunofluorescence results showed that the islet cells in the blank group were arranged in an orderly and full shape with appropriate insulin secretion, while the islet cells in model group were distorted in shape, atrophy in structure and less insulin secretion. The insulin content of mice in JTTP and metformin group was significantly increased. Compared with blank group, mRNA expressions of NLRP3, apoptosis-related spot-like protein (ASC) and Caspase-1 in pancreatic tissues of model group were significantly increased (P<0.01). Compared with model group, JTTP high-dose group and metformin group promoted the up-regulation of TGR5 and cAMP mRNA, and down-regulated the mRNA expressions of NLRP3, ASC and Caspase-1 (P<0.05, P<0.01). Compared with blank group, the expression of TGR5 protein in model group was significantly decreased (P<0.01). Compared with model group, TGR5 protein in JTTP high-dose group and metformin group was significantly increased (P<0.01).
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ObjectiveThis study aims to investigate the mechanism in which Celastrus orbiculatus extract (COE) affects the proliferation and differentiation of gastric organoids and the expression of Lgr5 and thus reverses the precancerous lesions of gastric cancer (PLGC) by regulating the leucine-rich repeat containing G protein-coupled receptor 5 (Lgr5)/Wingless (Wnt)/β-catenin signaling pathway based on a gastric organoid injury model. MethodGastric organoids were established based on stem cells of the mouse gastric gland. Gastric organoid injury models were constructed by treating gastric organoids with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG, 0.02 mg·L-1). Gastric organoid injury models were randomly divided into normal group, model group (0.02 mg·L-1 MNNG), low, medium, and high dose (5, 10, 20 mg·L-1) groups of COE, and Wnt inhibitor Dickkopf-related protein 1 (DKK1) (0.5 mg·L-1) group, and they were treated with respective agents for 24 h. The number and volume of gastric organoids under different drug concentrations were observed under a microscope. The viability of the gastric organoid injury models was detected by Methyl thiazolyl tetrazolium (MTT) assay. The morphology and pathology of gastric organoids were observed using Hematoxylin and Eosin (HE) staining. The expression levels of Lgr5, Mucin2 (MUC2), Mucin5AC (MUC5AC), Mucin6 (MUC6), Wnt, and β-catenin in gastric organoids under different drug concentrations were detected by Western blot (WB). ResultCompared with the normal group, the number, volume, and activity of gastric organoids in the model group were decreased (P<0.01), while the expressions of Lgr5, MUC2, Wnt, and β-catenin were significantly increased (P<0.01). The expressions of MUC5AC and MUC6 were significantly decreased (P<0.01). Compared with the model group, the number and volume of gastric organoids in the low, medium, and high dose groups of COE were all improved (P<0.01), and the vitality of gastric organoids was significantly enhanced (P<0.01). The effect was the most significant at a COE concentration of 20 mg·L-1 (P<0.01). The expressions of Lgr5 and MUC2 in the medium and high dose groups of COE were significantly reduced (P<0.01), while the expression of MUC5AC and MUC6 were significantly increased in the low, medium, and high dose groups of COE (P<0.05, P<0.01). Compared with the model group, Wnt inhibitors could promote the expression of MUC5AC and MUC6 in gastric organoids (P<0.05, P<0.01) and reduce the expression of MUC2, Wnt, and β-catenin. In addition, the combined use of COE at high concentrations and Wnt inhibitors could further promote this trend (P<0.01). ConclusionCOE inhibits the Wnt/β-catenin pathway by inhibiting the expression of Lgr5, MUC2, Wnt, and β-catenin and promoting the expression of MUC5AC and MUC6, thus promoting the proliferation and differentiation of gastric organoids and reversing the PLGC process.
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ObjectiveTo investigate whether paeonol exerts a protective effect on mice with alcoholic liver injury by regulating the takeda G-protein-coupled receptor 5 (TGR5)/protein kinase A (PKA)/cAMP response binding element (CREB) signaling pathway mediated by Eubacterium. MethodC57BL/6 mice were randomly divided into five groups: normal group, model group, paeonol group (480 mg·kg-1), antibiotic group (Abs group), and antibiotic + paeonol group. Lieber-DeCarli liquid was used to feed C57BL/6 mice on the second day of modeling for 10 days. The blood lipids, liver function, inflammatory factors, and oxidative stress levels in mice were measured. Hematoxylin-eosin staining (HE) and oil red O staining were used to observe the morphological changes and fat accumulation in liver tissue. 16S rDNA sequencing was used to detect the diversity of intestinal microbiota in the blank, model, and paeanol groups. Western blot was used to detect the effect of paeonol on the expression levels of protein related to the signaling pathway of atresia band protein 1 (ZO-1), Claudin-1, and TGR5/PKA/CREB in mouse ileal tissue. ResultCompared with those in the blank group, the blood lipids, liver function, oxidative stress levels, and the expression of inflammatory factors in the model group increased (P<0.01), and the liver fat vacuoles were obvious. The ileal mucosa was seriously damaged, and the protein contents of ZO-1, Claudin-1, and TGR5/PKA/CREB in the ileal tissue decreased significantly (P<0.01). The intestinal microbiota changed, and the proteobacteria phylum increased significantly. The ratio of Bacteroidetes to Firmicutes decreased. The relative abundance of Dubosiella newyorkensis, Lactobacillus, Bifidobacterium, and other genera decreased, while the relative abundance of Escherichia-Shigella, Morganella, Providencia, and Proteus increased significantly. Compared with the model group, paeonol significantly reduced the blood lipids, liver function, oxidative stress levels, and expression of inflammatory factors in mice with alcohol diet-induced liver injury (P<0.05), decreased liver fat vacuoles, improved and restored the ileal intestinal barrier, and restored the normal structure of hepatocytes and ileal cells. The intestinal microbiota disorder caused by alcohol was improved, and the relative abundance of beneficial bacteria such as Eubacterium spp. was increased. The protein expression levels of ZO-1, Claudin-1, and TGR5/PKA/CREB in ileal tissue were increased (P<0.05). ConclusionPaeonol has a protective effect on alcoholic liver injury in mice, and the mechanism of action is achieved by regulating the Eubacterium-mediated TGR5/PKA/CREB signaling pathway to ensure anti-inflammatory effect and improve the intestinal barrier.
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Objective·To analyze the expression changes of adhesion G protein-coupled receptor F1(ADGRF1)in the occurrence and development of pancreatic ductal adenocarcinoma(PDAC),and explore the impact of ADGRF1 on the proliferation of PDAC cells and the potential molecular mechanisms that promote PDAC progression.Methods·The expression of ADGRF1 at mRNA level was analyzed based on the Gene Expression Omnibus(GEO)database and The Cancer Genome Atlas(TCGA)database,respectively.The expression of ADGRF1 in normal pancreatic ductal epithelial cells(hTERT-HPNE)and various PDAC tumor cells was detected by using real-time fluorescence quantitative PCR(qPCR)and Western blotting.Immunohistochemical staining(IHC)was used to detect the differential expression of ADGRF1 in cancer tissues and adjacent tissues of PDAC patients.After knocking down ADGRF1 with small interfering RNA(siRNA)transfection,the changes in the proliferation ability of PDAC AsPC-1 and SW1990 cells were detected through CCK8 assay and plate cloning experiment.Stable overexpression of ADGRF1 was constructed in PDAC Patu8988 cell line,and the proliferation changes induced by overexpression of ADGRF1 were evaluated through CCK8 assay.RNA sequencing(RNA-seq),gene set enrichment analysis(GSEA),and immune infiltration analysis were utilized to predict signaling pathways associated with ADGRF1-mediated promotion of PDAC cancer progression.Results·Analysis of the TCGA database and GEO database revealed higher expression of ADGRF1 mRNA in PDAC tissues compared to normal pancreatic tissues(all P=0.000).qPCR and Western blotting results demonstrated up-regulation of ADGRF1 mRNA and protein levels in various PDAC cells compared to hTERT-HPNE cells(all P<0.05).IHC results confirmed higher ADGRF1 expression in PDAC cancer tissues compared to adjacent tissues.Furthermore,downregulation of ADGRF1 inhibited the proliferation of PDAC AsPC-1 and SW1990 cell lines,while overexpression of ADGRF1 promoted the proliferation of Patu8988 cells(all P<0.05).RNA-seq,GSEA enrichment analysis,and immune infiltration analysis revealed that ADGRF1 expression was related to signaling pathways such as interferon-α(IFN-α),tumor necrosis factor-α(TNF-α),and nuclear factor κB(NF-κB).Conclusion·ADGRF1 is highly expressed in PDAC cells and tissues,and promotes the proliferation of PDAC cells via immune-related signaling pathways.
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Objective:To analyze the epidemiological features of respiratory syncytial virus (RSV) infection in Beijing, and monitor the sequence variations in RSV glycoprotein (G) gene and clinical features of infected children.Methods:Respiratory tract specimens were collected from children with acute respiratory infection in the Children′s Hospital Affiliated to Capital Institute of Pediatrics from January 1, 2023 to December 31, 2023. RSV-positive specimens screened by multiple nucleic acid testing were subjected to PCR to amplify the full-length RSV G gene. A phylogenetic tree was constructed after gene sequencing to analyze RSV subtypes and trace G gene variants. Clinical data were retrieved from the medical record system to analyze the clinical features of children with RSV infection in Beijing.Results:A total of 5 489 respiratory specimens were collected from 3 046 male patients and 2 443 female patients. The average age of the patients was 4.36 years. A total of 589 RSV-positive specimens (10.7%, 589/5 489) were detected with 349 from male patients and 240 from female patients. The average age of children with RSV infection was (2.51±2.78) years and the median age was 0.48 years. RSV had been circulating among children in Beijing since March 2023 with two epidemic peaks in May (24.6%, 122/496) and December (18.2%, 126/693). The predominant subtype of RSV in the first half of 2023 was subtype A, but it was replaced by subtype B from November 2023. Phylogenetic analysis revealed a novel G gene of RSV subtype B (RSV-B-BA9-954bp) with a length of 954 bp, which belonged to a new cluster in the phylogenetic tree. The percentage of patients admitted to the Intensive Care Unit (ICU) was higher in children with new variant of RSV subtype B infection than in those with common RSV subtype B infection [44.1% (15/34) vs 25.2% (31/123), χ 2=4.600, P=0.032], while the counts of white blood cells and the levels of C-reactive protein were lower in the children with new variant infection ( P<0.05). Conclusions:RSV has been prevalent among children in Beijing since March 2023 with two epidemic peaks. The predominant A subtype is gradually replaced by to B subtype. A new variant of RSV B G gene (RSV-B-BA9-954bp) is detected among the children.
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@#Abstract: Olfactory receptors (ORs) are transmembrane proteins mainly distributed in olfactory sensory neurons of the nasal epithelium, mediating the transmission of real-time sensory signals to the brain to produce smell. Recent studies have reported that ORs can also be expressed in tissues or organs outside the nasal cavity, and are closely related to a variety of biological processes, such as sperm chemotaxis, wound healing, glycolipid metabolism and intestinal secretion. In addition, ORs are closely related to a variety of malignant tumors such as prostate cancer, breast cancer and colorectal cancer, and may affect the occurrence and development of tumors by regulating cell proliferation, apoptosis, migration and invasion. This review provides an overview of the effects of ectopic ORs on the function of various human tissues and organs and assesses their potential value as drug targets for the treatment of human diseases.
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Aim To establish a stable hepatic stellate cell ( HSC ) -specific G protein-coupled receptor kinase 2 ( GRK2 ) knockout mice and provide the important animal model for further studying the biological function of GRK2 in HSC. Methods The loxP-labeled Grk2 gene mouse (Grk2
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GPCRs are the largest membrane protein receptor superfamily in the human body, with more than 800 isoforms, and approximately 35% of Food and Drug Administration-approved and marketed drugs currently target GPCRs for the treatment of a wide range of diseases, for heart failure (beta-adrenergic receptors), peptic ulcer (histamine receptors), prostate cancer (gonadotropin receptors), hypertension (adrenergic and angiotensin receptors), pain (opioid receptors), and bronchial asthma (beta2-adrenergic receptors) examples. Although the number of GPCRs is enormous, the signaling proteins downstream of them are limited, heterotrimeric G proteins (GPs) are key proteins that signal GPCRs, translate extracellular stimuli into intracellular responses by coupling to GPCRs and initiate multiple signaling events via downstream cascades. Podocytes are an important component of the glomerular filtration barrier, and their damage is a central event in proteinuria formation and progressive glomerulosclerosis. This article reviews the regulation of GPs, their signaling and their role in podocyte injury to provide a theoretical basis for scientific research and clinical treatment of this disease.
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ABSTRACT Background: Bile acids (BAs) are steroid molecules synthesized exclusively in the liver, being end products of cholesterol catabolism. BAs are known to be involved in several metabolic alterations, including metabolic syndrome and type 2 diabetes mellitus (DM2). DM2 is a chronic degenerative disease characterized by insulin resistance, insulin deficiency due to insufficient production of pancreatic ß-cells, and elevated serum glucose levels leading to multiple complications. Objective: The objective of this study is to investigate the role of BAs in the pathophysiology of DM2, highlighting the possibilities in the development of therapeutic procedures targeting BAs as an optional pathway in the treatment of DM2. Methods: The research was carried out through narrative review and publications on the relationship between BAs and DM2. The databases used for the search include PubMed, Scopus, and Web of Science. The keywords used for the search include bile acids, type 2 diabetes mellitus, metabolic syndrome, and metabolic disorders. Results: The studies have reported the involvement of BAs in the pathophysiology of DM2. BAs act as a ligand for the nuclear farnesoid X receptor, regulating glucose metabolism, lipid metabolism, and cellular energy production. Additionally, BAs modulate the production, elimination, and mobilization of BAs through the farnesoid X receptor. BAs also act as a signaling pathway through Takeda G protein-coupled receptor 5, further contributing to metabolic regulation. These findings suggest that targeting BAs may offer a novel therapeutic approach in the treatment of DM2. Conclusion: This study highlights the important role of BAs in DM2, specifically through their interactions with key metabolic pathways. Targeting BAs may represent an innovative and effective approach to the treatment of DM2.
RESUMO Contexto: Os ácidos biliares (ABs) são moléculas esteróides sintetizadas exclusivamente no fígado, sendo produtos finais do catabolismo do colesterol. Os ABs são conhecidos por estarem envolvidos em várias alterações metabólicas, incluindo a síndrome metabólica e o diabetes mellitus tipo 2 (DM2). A DM2 é uma doença crônica degenerativa caracterizada pela resistência insulínica, deficiência de insulina devido à produção insuficiente de células ß pancreáticas e hiperglicemia levando a múltiplas complicações. Objetivo: O objetivo deste estudo é investigar o papel dos ABs na fisiopatologia da DM2, destacando as possibilidades no desenvolvimento de procedimentos terapêuticos visando os ABs como uma via opcional no tratamento da DM2. Métodos: A pesquisa foi realizada por meio de revisão narrativa e publicações sobre a relação entre ABs e DM2. As bases de dados usadas para a pesquisa incluem PubMed, Scopus e Web of Science. As palavras-chave usadas para a pesquisa incluíram: ácidos biliares, diabetes mellitus tipo 2, síndrome metabólica e distúrbios metabólicos. Resultados: Os estudos relataram o envolvimento dos ABs na fisiopatologia da DM2. Os ABs atuam como ligantes para o receptor nuclear farnesoide X, regulando o metabolismo da glicose, metabolismo lipídico e produção de energia celular. Além disso, os ABs regulam a produção, eliminação e mobilização de ABs através do receptor farnesoide X. Os ABs também atuam como uma via de sinalização através do receptor acoplado à proteína G Takeda 5, contribuindo ainda mais para a regulação metabólica. Esses achados sugerem que o ABs pode oferecer uma nova abordagem terapêutica no tratamento da DM2. Conclusão: Este estudo destaca o papel importante do ABs na DM2, especificamente por meio de suas interações com vias metabólicas-chave. O redirecionamento ao ABs pode representar uma abordagem inovadora e eficaz para o tratamento da DM2.
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Objectives: Centrally-acting antitussives with inhibitory effects on G protein-coupled inwardly rectifying potassium (GIRK) channels have been shown to also inhibit methamphetamine-induced hyperactivity in mice. In this study, we examined if cloperastine, which is the most potent inhibitor of the GIRK channels among antitussives, is sensitive to the expression levels of GIRK channels in the brain of methamphetaminetreated mice. Materials and Methods: The brain tissues have been removed and the total RNA has been extracted from tissues. The mRNA levels were evaluated using semiquantitative reverse transcription-polymerase chain reaction. Results: The concentration levels of the mRNA of GIRK channels within the ventral midbrain of methamphetamine-treated mice increased as compared with that in control and cloperastine reduced an upregulation in GIRK2, one of the subunits of the GIRK channels, by the injection of methamphetamine. Conclusion: These findings suggest that cloperastine might ameliorate hyperactivity by inhibiting the GIRK channels in the brain.
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Stroma surrounding the tumor cells plays crucial roles for tumor progression. However, little is known about the factors that maintain the symbiosis between stroma and tumor cells. In this study, we found that the transcriptional regulator-signal transducer and activator of transcription 3 (Stat3) was frequently activated in cancer-associated fibroblasts (CAFs), which was a potent facilitator of tumor malignancy, and formed forward feedback loop with platelet-activating factor receptor (PAFR) both in CAFs and tumor cells. Importantly, PAFR/Stat3 axis connected intercellular signaling crosstalk between CAFs and cancer cells and drove mutual transcriptional programming of these two types of cells. Two central Stat3-related cytokine signaling molecules-interleukin 6 (IL-6) and IL-11 played the critical role in the process of PAFR/Stat3 axis-mediated communication between tumor and CAFs. Pharmacological inhibition of PAFR and Stat3 activities effectively reduced tumor progression using CAFs/tumor co-culture xenograft model. Our study reveals that PAFR/Stat3 axis enhances the interaction between tumor and its associated stroma and suggests that targeting this axis can be an effective therapeutic strategy against tumor malignancy.
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Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. Fat accumulation "sensitizes" the liver to insult and leads to nonalcoholic steatohepatitis (NASH). G protein-coupled receptor 35 (GPR35) is involved in metabolic stresses, but its role in NAFLD is unknown. We report that hepatocyte GPR35 mitigates NASH by regulating hepatic cholesterol homeostasis. Specifically, we found that GPR35 overexpression in hepatocytes protected against high-fat/cholesterol/fructose (HFCF) diet-induced steatohepatitis, whereas loss of GPR35 had the opposite effect. Administration of the GPR35 agonist kynurenic acid (Kyna) suppressed HFCF diet-induced steatohepatitis in mice. Kyna/GPR35 induced expression of StAR-related lipid transfer protein 4 (STARD4) through the ERK1/2 signaling pathway, ultimately resulting in hepatic cholesterol esterification and bile acid synthesis (BAS). The overexpression of STARD4 increased the expression of the BAS rate-limiting enzymes cytochrome P450 family 7 subfamily A member 1 (CYP7A1) and CYP8B1, promoting the conversion of cholesterol to bile acid. The protective effect induced by GPR35 overexpression in hepatocytes disappeared in hepatocyte STARD4-knockdown mice. STARD4 overexpression in hepatocytes reversed the aggravation of HFCF diet-induced steatohepatitis caused by the loss of GPR35 expression in hepatocytes in mice. Our findings indicate that the GPR35-STARD4 axis is a promising therapeutic target for NAFLD.
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With the rapid increase in the prevalence rate of nonalcoholic fatty liver disease (NAFLD), new treatment methods are needed to prevent disease progression to liver fibrosis, liver cirrhosis, and liver cancer. Although great efforts have been made to clarify the pathological mechanisms of NAFLD disease progression, there are still no effective treatment methods at present. Bile acids (BAs) regulate systemic metabolism by activating nuclear receptors and G protein-coupled receptors and have been identified as important signaling molecules involved in lipid, glucose, and energy metabolism. Dysregulation of BA homeostasis is associated with the severity of NAFLD. This article summarizes the important ligands in BA metabolism and their role in the progression of NAFLD, in order to provide a basis for the treatment of NAFLD by targeting BA messengers.
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ObjectiveTo observe the changes in the expression and distribution of G protein-gated inwardly rectifying potassium channel subunit 2 (GIRK2) in the dorsal root ganglion (DRG) and spinal cord dorsal horn of rats with remifentanil-induced hyperalgesia. MethodsHyperalgesia was induced by intravenous infusion of remifentanil 4 μg/kg/min for 2 h in adult male SD rats. At 6th hour and on days 1, 3 and 5 following remifentanil treatment, we used immunofluorescence to examine the changes in the GIRK2 distribution and expression. Immunoblotting was used to detect GIRK2 expression of the total protein and membrane protein in DRG and spinal dorsal horn of rats. Behavioral testing was applied to evaluate the effect of intrathecal injection of GIRK2-specific agonist ML297 on thermal nociceptive threshold on day 1 after remifentanil infusion. Resultsmmunofluorescence results showed that GIRK2 was mainly co-localized with IB4-positive small neurons in DRG and nerve fibers in spinal dorsal horn. GIRK2 expression was significantly downregulated following remifentanil treatment. Immunoblotting results revealed that on day 1 following intravenous infusion of remifentanil, compared with those in the control group, GIRK2 expression levels of the total protein and membrane protein in DRG (0.47 ± 0.10 vs. 1.01 ± 0.17, P < 0.001; 0.47 ± 0.11 vs. 1.06 ± 0.12, P < 0.001) and spinal dorsal horn (0.52 ± 0.09 vs. 1.10 ± 0.08, P < 0.001; 0.54 ± 0.10 vs. 1.01 ± 0.13, P < 0.001) were all significantly decreased. The behavioral results showed that intrathecal ML297 effect on thermal withdrawal latency was significantly reduced following remifentanil treatment (P < 0.001). ConclusionsRemifentanil might induce hyperalgesia via down-regulating GIRK2 expression in rat DRG and spinal cord dorsal horn.
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@#Free fatty acid receptors(FFARs)are a series of orphan G protein-coupled receptors(GPCRs)activated by free fatty acids(FFAs)and their derivatives. As transmembrane receptors,GPCRs are involved in the occurrence and development of many diseases and provide a wide range of therapeutic targets for these diseases. FFARs combined with FFAs are mainly involved in the secretion of endocrine hormones such as insulin,adipocyte differentiation,inflammatory response,autoimmune response and other processes,which was a potential therapeutic target for energy metabolism disorders and immune diseases. However,recent studies have shown that FFAs and its receptor FFARs are widely involved in neuroinflammation and neuroimmunity directly or through the brain-intestinal axis,and are expected to be a therapeutic target for multiple sclerosis,Alzheimer′s disease(AD),Parkinson′s disease(PD),depression and other diseases. This paper reviews the research progress of the role of FFARs in nervous system diseases.
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Nonalcoholic fatty liver disease (NAFLD) has gradually become a prominent cause affecting human liver health, and the development and progression of NAFLD are associated with metabolic dysfunction, with glucose and lipid metabolism disorder as the key link in this process. Takeda G protein-coupled receptor 5 (TGR5) is one of the main receptors of bile acid and is extensively expressed in the body, and glucose and lipid metabolism mediated by TGR5 plays an important role in the human body. This article summarizes the role and mechanism of TGR5 in glucose and lipid metabolism and the research findings of the treatment of NAFLD based on TGR5, in order to provide a reference for basic and clinical research.
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OBJECTIVE To study the effects and potential mechanism of anaphylactoid reaction induced by nonapeptide IVQKIKHCF activating mast cells. METHODS Using human mast cell line LAD2 as subject, and substance P as positive control, the activation effects of 25, 50 and 100 μmol/L IVQKIKHCF on mast cells were investigated by determining the release rate of β-aminohexosidase, histamine release, and the contents of inflammatory factors; using MrgprX2-knockdown LAD2 cells and Mas- related G protein-coupled receptor X2 (MRGPRX2) high-expression human embryonic kidney cell line HEK293 (MRGPRX2/ HEK293 cells) as subject, the correlation between the activation effect of IVQKIKHCF and MRGPRX2 was investigated by determining the release rate of β-aminohexosidase, and intracellular calcium ion concentration. RESULTS IVQKIKHCF with 25, 50, 100 μmol/L could significantly increase the release rate of β-aminohexosidase and histamine release in LAD2 cells (P<0.05), and promote the release of tumor necrosis factor-α, interleukin-8, macrophage inflammatory protein-1β and monocyte chemotactic protein-1 to varying degrees (P<0.05). After knocking down MrgprX2, the effects of 25, 50, 100 μmol/L IVQKIKHCF promoting the release of β-aminohexosidase in LAD2 cells were reversed significantly (P<0.05), resulting in an increase of calcium ion concentration in MRGPRX2/HEK293 cells. CONCLUSIONS Nonapeptide IVQKIKHCF can promote mast cells to release granular matter and inflammatory mediators by activating MRGPRX2 thus inducing anaphylactoid reaction.
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ObjectiveTo discuss the effect of modified Gegen Qinliantang (MGQT) on blood glucose and lipids and Takeda G protein-coupled receptor 5 (TGR5)-related pathways in pancreatic tissue of obese type 2 diabetes mellitus (T2DM) mice. MethodA total of 10 male specific pathogen free (SPF) m/m mice (7 weeks old) and 50 male SPF (7 weeks old) were adaptively fed for one week in SPF laboratory. The m/m mice were included in the blank group. T2DM was induce d in the 50 db/db mice. The model mice were randomized into the model group, metformin group (0.2 g·kg-1), high-dose, medium-dose, and low-dose (31.9, 19.1, 6.4 g·kg-1) MGQT groups, with 10 in each group, and the drug dose was10 mL·kg-1. The model group and the blank group received distilled water of the same volume. The administration lasted 12 weeks (once/day). Fasting blood glucose (FBG) was detected regularly. After 12 weeks of administration, serum levels of glycated serum protein (GSP), serum glucose (GLU), total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were detected. Pathological changes in the pancreatic tissue were based on hematoxylin-eosin (HE) staining. Western blot was used to determine the protein expression of TGR5, protein kinase A (PKA), phosphorylated (p)-PKA, cyclic-AMP response element binding protein (CREB), p-CREB, proprotein convertase 1/3 (PC1/3), and glucagon-like peptide-1 (GLP-1) in pancreatic tissues. The level of cyclic adenosine monophosphate (cAMP) in pancreatic tissue was determined by enzyme-linked immunosorbent assay (ELISA). ResultCompared with the blank group, the model group had pathological changes in pancreatic tissue, high levels of FBG, GSP, GLU, TC, TG, and LDL-C (P<0.01), low level of HDL-C (P<0.05), low protein expression of TGR5, p-PKA (Thr197)/PKA, p-CREB (Ser133)/CREB, PC1/3, and GLP-1 in pancreatic tissue (P<0.01), and low content of cAMP in the pancreas (P<0.01). Pancreatic tissue lesion in the treatment groups were milder than that in the model group. Both the high-dose MGQT and metformin can reduce the levels of FBG, GSP, GLU, TC, TG, and LDL-C in db/db mice (P<0.05, P<0.01) and increase the level of HDL-C (P<0.01). Except the GLP-1 protein in the medium-dose MGQT group, the protein expression of TGR5, p-PKA (Thr197)/PKA, p-CREB (Ser133)/CREB, PC1/3, and GLP-1 in the high-dose and medium-dose MGQT groups and the metformin group increased compared with that in the model group (P<0.05, P<0.01). The content of cAMP in the pancreatic tissue of the high-dose and medium-dose MGQT groups and the metformin group was raised compared with that in model group (P<0.05, P<0.01). ConclusionMGQT can improve the glucose homeostasis in db/db mice with T2DM by regulating TGR5/cAMP/GLP-1 signaling pathway-related protein expression.
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Parkinson's disease (PD) is a degenerative disease of the central nervous system due to the loss or death of dopaminergic neurons in the substantia nigra. Clinically, levodopa is the most effective and commonly used drug for PD treatment. However, long-term levodopa therapy is prone to motor complications and other side effects caused by excessive peripheral dopamine production, which has become an urgent problem to be solved in PD treatment. Dopamine receptor (DR) agonists are similar to dopamine. They can directly stimulate postsynaptic dopamine receptors, produce the same effect as dopamine, delay the application of levodopa as much as possible, and reduce complications caused by long-term use of levodopa. Therefore, screening effective dopamine receptor agonists has become a key issue in the study and treatment of PD. In order to establish a rapid, stable and reliable method for dopamine receptor agonist screening, this study used the human dopamine receptor 2 (DRD2) gene fused with a circular permuted EGFP (cpEGFP) to construct a recombinant gene, packaged with lentiviral vector, and the vector replaced the parted inner transmembrane domain of the third intracellular loop (ICL3) of genetically-encoded GPCR-activation based (GRAB) sensors. The fluorescence of GPCR-fused cpEGFP is regulated by conformational changes mediated by the interaction of dopamine receptor agonists with GPCRs without altering GPCR activity. The HEK293T cells were infected with viral vector, screened by puromycin to select highly expressed cells. Dopamine receptor agonists (including dopamine, bromocriptine mesylate, cabergoline, pramipexole) were used as positive drugs to explore the best screening and detection conditions, establishing a stable model to evaluate the dopamine receptor agonist. The results showed that the optimal filter for the dopamine receptor agonist in this study was the cell seeding count of 7×104, and the effective concentration of the positive drug was 1-100 µmol·L-1. In addition, pretreated with 10 µmol·L-1 dopamine receptor antagonists (including chlorprothixol hydrochloride, domperidone, and sulpiride), the positive fluorescence signal of overexpressed DRD2-cpEGFP HEK293T cells could not be detected when exposed to 10 µmol·L-1 dopamine receptor agonists, which proved that dopamine receptor antagonists could block the activity of dopamine receptor agonists, so they cannot activate dopamine receptor allosteric, indicating that the model has good specificity and can also be used for the screening and detection of new dopamine receptor antagonists. In summary, the study constructs a stable dopamine sensor detection system, which can effectively screen potential dopamine receptor agonists. The operation procedures are simple and rapid. And it can be used for a large-scale screening providing a fundamental methodology for drug development and PD treatment targeted on DRD2.